1. Field of the Invention
The invention relates in general to computer systems, and more particularly, to a provision for continuous database service using active redundant copies of the database.
2. Description of Related Art
Many modern computer systems are in nearly continuous use, and have very little time to be taken "down" or "offline" for database updates or preventative maintenance. Further, computer systems increasingly require systems that virtually never fail and have little or no scheduled downtime. As a concurrent requirement, these same systems demand cost-effective computing solutions, open systems to avoid or reduce specific supplier dependencies, and the ability to leverage the latest hardware and software technologies as they become available.
Modern computer systems also have transitioned from a static installation to a dynamic system that regularly changes. The system continually contains new collections of products that are processing requests from a constantly changing user base. The ability of computing solutions to provide service availability in a dynamic environment is becoming increasingly important, because the pace of change in products and customers' environments is expected to increase. The term "change tolerance" has been used to describe the ability of a computer system to adapt to the dynamic environment required.
It can be seen, then, that there is a need in the art for a system that provides a high confidence level for continuous processing. It can also be seen, then, that there is a need in the art for a system with a high change tolerance. It can also be seen, then, that there is a need in the art for a system with reasonable development costs and implementation schedules that does not sacrifice the benefits of open systems.